Aqueous polyvinyl acetal dispersions

摘要

An aqueous dispersion (I) of a carboxyl group containing polyvinyl acetal (II) is claimed. (I) contains no emulsifier, volatile organic solvent or non-volatile plasticiser and is prepared by reaction of a hydroxyl group containing polyvinyl acetal with a polycarboxylic acid anhydride in the melt or in a high boiling solvent followed by at least partial neutralisation and dispersion of the resulting salt in water.